Heater Box Woes... Doors Inside Heater Box.. Vacuum Lines

Stang_1973

Founding Member
Jul 13, 2001
557
8
38
San Antonio, Tx.
Ok so ive been trying to get around to fixing a few things in my car one of which is figuring out why i always have air coming in through the defrost vents. now my a/c has never worked. hopefully next year i can get the system fixed. however right now that i have the entire dash pulled out i decided to look into why air is always blowing through my defrost vent even with the blower off. it blows faster with how fast you are driving and is generally hotter than the outside air.

so this is what ive found. i began to inspect the heater box and noticed the main door that leads to the "outside air" is always open. this i figure as something to do with the vacuum motors not engaging to close that door.

next if found that there are 2 more doors inside the heater box. one which ive been able to ID as the Blend door and is operated by the cool/warm lever on the control unit.

the other door is acutally completely missing. Does anyone know what that door is called?trying to find the replacement. also it looks like it too hooks up to a vacuum motor.

lastly one other thing that i think has to do with the vacuum motors not working is that while they are all connected inside on the distrubution block and the motors, i found one pretty corroded and disconnected vacuum line that comes through the firewall and is connected to nothing. i assume its coming from the distribution block/controller and should be getting vaccum from the motor? but i dont know where it should hook up.
 
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Sounds like the vacuum to the heater control is disconnected . There is a can inside the pass side fender apron ,looks like a coffee can. It will have two nipples coming through the fender apron near the hood hinge. One goes to the back of the intake and the other will go inside the car through the fire wall and hooks to the vacuum part of the heater control. The hoses probably rotted off and were plugged .You can test the vacuum motor with a vacuum tester to see if they are good . Cant help you with the missing door .
 
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